This invention relates to telephones in general, and in particular two or more telephones communicating using an IP protocol.
An IP softphone consists of a software package running on a personal computer (PC). The software emulates a telephone and communicates signaling and voice information via a IP-network connection between the PC and a telecommunication switching system (also referred to as a PBX). This network connection is often the Internet or a LAN. Audio information being received from the network is communicated with the user via a headset or handset via a sound card that interfaces the headset or handset to the PC. When a user speaks, the sound card converts the analog information into digital information that the software then transmits to a destination via the network. When a call is received via the network for the IP softphone, the software alerts the user via a speaker attached to the PC. The user then answers the call by selecting the softphone software application and selecting a soft button labeled xe2x80x9canswerxe2x80x9d. The user then conducts a conversation with the caller via either the handset or the headset. To place a call, the user once again selects the software and selects a soft button labeled xe2x80x9cNumberxe2x80x9d and proceeds to dial the destination number using a keypad or a pre-stored list of telephone numbers. The keypad can by either a soft keypad or the PC""s keyboard.
A common problem is that while a user is walking into their office, they then hear the IP softphone ringing. To answer the call, the user must unlock the screen blanker to access the PC, select the software application, and actuate the soft button labeled xe2x80x9canswerxe2x80x9d. Then, the user can pick up the handset or the headset and talk. The problem is that a great amount of time is involved in performing these steps. Frequently, before the user has completed the steps, the call is transferred to coverage such as a voice mail system.
An apparently obvious solution would be to have a switch in the handset that was activated when the handset was picked up to answer the call. However, the vast majority of sound cards do not have a physical input that can sense a switch. One solution that has been utilized is in the Microsoft Netmeeting application. Microsoft Netmeeting attempts to solve this problem by having an option referred to as xe2x80x9ccall, automatically accept callsxe2x80x9d. Utilizing this option, a user need only start listening and talking in order to participate in the call. The disadvantage of this option is that a call is always answered whether or not the user is available or not. This leads to a great deal of frustration for callers if the user is not there. Further, at times, the called party may simply not want to answer the call at a particular time.
This invention is directed to solving these and other problems and disadvantages of the prior art. According to the invention, a handset has a switch that is manually activated when the user wishes to answer an incoming call. While the switch is in the deactivated state, the handset transmits to a sound card within a personal computer a multi-frequency tone which is detectable by the sound card. When the manual switch is activated, the handset ceases to transmit the multi-frequency tone to the sound card. The sound card detects the absence of the multi-frequency tone to determine if the handset is answering a call. In traditional telephony terms, when the manual switch is activated, this is the offhook condition. When the manual switch is deactivated, this is the onhook condition . When the user is done with the call and deactivates the manual switch, the handset again generates the multi-frequency tone that is subsequently detected by the software via the sound card. Then, the software knows to signal the other party on the call that the call has been terminated. A headset is similarly designed to provide the same multi-frequency tone generation features as the handset.